Troubleshooting - Honda Hawk GT NT650 1988 Service Manual

20. TROUBLESHOOTING
ENGINE DOES NOT START
ENGINE IS HARD TO START OR
SOON STOPS
ENGINE LACKS POWER WITH
NORMAL LOADING
ENGINE DOES NOT START
20-1
20-2
20-3
POOR ENGINE PERFORMANCE AT
LOW AND IDLE SPEEDS
POOR ENGINE PERFORMANCE AT
HIGH SPEEDS
POSSIBLE CAUSE
20-5
20-6
WEAK OR NO SPARK------....,....,· .-Refer to page 16-2
WET PLUG - - - - - - - - - - _ " ' . Mixture too rich
Carburetor flooded
Choke valve stuck open
Cylinder flooded
Dirty air cleaner
ENGINE STA R T S . _ - - - - - - - -....• Faulty choke system
Fuel contaminated
Carburetor incorrectly adjusted
Intake pipe leaking
Clogged carburetor passage or jets
1. Drain float chamber and check flow NOT REACHING CARBURETOR---....-· Clogged fuel line or fuel filter/
to carburetor. strainer
I
Clogged fuel tank breather hole
REACHING CARBURETOR Loose or disconnected fuel pump
and relay wire
Faulty fuel pump relay
Faulty fuel pump
Sticking float valve
Faulty float
Clogged carburetor body
2. Check spark plug
I
NO PROBLEM
I
3. Perform the spark test
I
GOOD SPARK
~
4. Pour 1-2 cc (0.03-0.06 US
OZ,
0.04-0.07 Imp
OZ)
fuel into
cylinders through the spark plug
hole, reinstall spark plugs and try
to start engine without choke
applied, with full-throttle.
I
ENGINE DOES NOT START
•
5. Test cylinder compression using LOW COMPRESSION----------l..
~ ·
Valve stuck open
compression gauge Damaged cylinder head gasket
I
Improper valve timing
~
COMPRESSION NORMAL Improper valve and seat contact
~
I
Worn cylinder and piston rings
Damaged piston
- - - - - - - - - - - - - - - - - - - - - - - - - - - - " ' . Improper ignition timing
(Faulty pulse rotor or generator with
ferrous burrs)
20-1